1. Field
The present invention relates to a method of manufacturing a mask assembly for thin film deposition.
2. Description of the Related Art
In general, among flat panel displays, an organic light emitting display has a relatively fast response speed as well as a relatively wide viewing angle and excellent contrast.
The organic light emitting display realizes a color by emitting light through recombination of holes and electrons injected to an anode and a cathode in an emission layer, and has a deposition structure in which the emission layer is positioned between the anode and the cathode. However, with this structure it is difficult to obtain high efficiency light emission. Accordingly, intermediate layers such as an electron injection layer (EIL), an electron transport layer (ETL), a hole transport layer (HTL), and a hole injection layer (HIL) may be selectively added between the electrode and the emission layer.
The intermediate layers, the electrodes, and the emission layer of the organic light emitting display may be formed by several methods, such as a deposition method. The deposition method is a method of depositing an original material of a thin film on a substrate through a fine metal mask (FMM) aligned to the substrate to form a thin film pattern.
The size of the fine metal mask may be increased as the size of the flat panel display is increased. As a large-sized fine metal mask may be formed using a division mask having several separate masks with a stick shape and attaching them in parallel to each other to a mask frame.
The division mask may be attached to the mask frame by spot welding. However, the welding process may deteriorate or warp the division mask, causing undesired separation between the division mask and the substrate.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.